1. Field of the Invention
An inflatable vehicular occupant safety restraint system in general and more particularly an inflatable rollover cushion for motor vehicles prone to rollover situations.
2. Description of the Related Art
U.S. Pat. No. 5,588,672 issued on Dec. 31, 1996 to Karlow et al and entitled xe2x80x9cSide Impact Head Restraint With Inflatable Deploymentxe2x80x9d shows a side curtain that is attached to the roof rail and has a slide that slides down the xe2x80x9cBxe2x80x9d pillar. When the system is to be deployed, a gas generator generates gas to inflate the curtain. As the gas fills the curtain, a slide moves along a track on the xe2x80x9cBxe2x80x9d pillar to a position immediately below the centerline of the side glass. This is the only movable point in the curtain because along the roof rail the curtain is secured. When the slide comes to the end of track, it locks in place securing the curtain along the xe2x80x9cBxe2x80x9d pillar. Depending upon the shape of the curtain, the curtain will extend from the end of the track to a fixed point along the roof rail above the door. An occupant""s head will strike the curtain that absorbs the head impact either by rebounding the head or giving way toward the glass.
U.S. Pat. No. 5,788,270 issued on Aug. 4, 1998 to Hxc3x85land and entitled xe2x80x9cSide Impact and Roll Over Inflatable Head Protectorxe2x80x9d describes an elongated curtain that has a slide that moves along a track on the xe2x80x9cBxe2x80x9d pillar. The curtain has a plurality of equally spaced inflatable tubes, that when inflated extend from the roofline to a position intermediate the height of the glass. An occupant""s head will strike the inflated curtain and be prevented from going through or out the window. The curtain in this embodiment has a web or a sheet that is not inflated, but rides with an inflatable portion as it is being inflated. The web extends from a point intermediate the length of the window to the xe2x80x9cAxe2x80x9d pillar so that only the rearward portion of the curtain is inflated. Several different size configurations are illustrated wherein each configurations extends from the roof rail to a point intermediate the height of the window.
At lest one major American car manufacturer has shown, at the Year 2000 International Auto Show in Detroit, Michigan, a mock-up of a potential side airbag curtain for some of its sport utility vehicles. The curtain extends from a position near the xe2x80x9cAxe2x80x9d pillar to a point adaptable to restrain the head of a rear passenger. Another American Car manufacturer has an article on page in the Automotive News, May 15, 2000, that it will install head curtain airbags manufactured by Autoliv Inc. on its 2001 cars.
It is a principal advantage is to manufacture a curtain from a lightweight material that is coated on the inside to retain the inflatable fluid.
It is yet another advantage to have a material that when formed into a gas-filled curtain will require less gas than similar curtains of substantially the same size because the material has less permeability.
It is still yet another advantage to provide a curtain that has a plurality of inflatable tubes extending either longitudinal or parallel to the upper door panel of the vehicle.
These and other advantages will become apparent from the inflatable rollover cushion for motor vehicles having a bag member formed from a single piece of lightweight material. The material is folded over and sealed along the mating open edges forming an enclosed member. Along each open seam is a xe2x80x9cYxe2x80x9d shaped tether member joining the bag edges together. The xe2x80x9cYxe2x80x9d shaped tether has displaceable upper arms joined together along a trunk. One open edge of the enclosed member lies along the upper arm of the xe2x80x9cYxe2x80x9d and along one side of the trunk and the other open edge lies along the other upper arm of the xe2x80x9cYxe2x80x9d and along the other side of the trunk. A bonding is used to secure the mating open edges along the xe2x80x9cYxe2x80x9d shaped tether member forming an enclosed member forming an elongated cylindrical member. An opening at one end of the bag member is adapted to receive inflation fluid for inflating the bag member. The inside surface of the folded bag member is coated with a gas retention material.